32

我正在使用 Android DownloadManger System Service 通过以下方式下载一些文件

dwnId = mgr.enqueue(new DownloadManager.Request(serveruri)
        .setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI |
                DownloadManager.Request.NETWORK_MOBILE)
                .setAllowedOverRoaming(false)
                .setTitle(getAlbumName())
                .setDescription(getTrackName())
                .setDestinationUri(deviceUri)
                .setShowRunningNotification(true));

mgr下载管理器实例在哪里,dwnId是返回的唯一 ID。我也在注册ACTION_DOWNLOAD_COMPLETE

registerReceiver(onDownloadComplete, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));

在 onDownloadComplete BroadcastReceiver 的 onReceive() 方法中,我得到了下载 ID

Long dwnId = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, 0);

之后,我正在向下载管理器查询下载状态

Cursor c = downloadManager.query(new DownloadManager.Query().setFilterById(dwnId)); c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS));

对于 DownloadManager.STATUS_* 常量。

问题是我两次收到相同的 downId(意味着 onReceive 方法被调用两次),一次是 DownloadManager.STATUS_SUCCESSFUL 状态,一次是相同 dwnId 的 DownloadManager.STATUS_FAILED 状态。我正在发出一次下载大约 10 个文件的请求,但在设备下载管理器上,它在通知栏左上角的意思中显示下载计数为 12 或 13。我认为下载管理器在下载文件时出现问题并恢复或自动重新启动以再次下载相同的文件。这就是为什么我请求下载的文件数量与下载队列中的实际数量之间存在差异的原因。因此,只有我两次获得相同的 DownloadId 完成操作。如果这是真的,如何限制它。我错了可能是我要求实际下载的计数差异的原因吗?为什么广播接收器两次收到相同的下载 ID。有人可以告诉我吗?

提前致谢...

4

3 回答 3

37

这是一个报告的错误,请参阅:http ://code.google.com/p/android/issues/detail?id=18462

我找到的方法是验证下载是否成功,如果没有放弃意图或重新排队文件,如果它从未下载过......

花了几个小时才弄清楚那个:(

** 编辑:添加代码示例 **

/**
 * Check if download was valid, see issue
 * http://code.google.com/p/android/issues/detail?id=18462
 * @param long1
 * @return
 */
private boolean validDownload(long downloadId) {

    Log.d(TAG,"Checking download status for id: " + downloadId);

    //Verify if download is a success
    Cursor c= dMgr.query(new DownloadManager.Query().setFilterById(downloadId));

    if(c.moveToFirst()){            
        int status = c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS));

        if(status == DownloadManager.STATUS_SUCCESSFUL){
            return true; //Download is valid, celebrate
        }else{
            int reason = c.getInt(c.getColumnIndex(DownloadManager.COLUMN_REASON));
            Log.d(TAG, "Download not correct, status [" + status + "] reason [" + reason + "]");            
            return false;
        }   
    }               
    return false;                                   
}

完整代码见:https ://github.com/flegare/JAV387_LaboWidget/blob/master/src/com/mobidroid/widgetfact/service/FactService.java

于 2012-04-15T20:33:23.590 回答
1

下载文件的简单方法,在通知栏中查看下载进度,甚至在完成下载后只需在通知栏中单击即可打开文件。

只需调用此方法并传递您的文件名和下载网址

 public void downloadFile(String name, String url){ 
        //download link
        downloadUri = Uri.parse(url);

        DownloadManager.Request request = new DownloadManager.Request(downloadUri);

        //allow download to take place over wifi, mobile network and roaming
        request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE ).setAllowedOverRoaming(true);
        request.setAllowedOverRoaming(false);

        //name to show while downloading
        request.setTitle(name);

        //description to show while downloading
        request.setDescription("Downloading " + name);

        //show on navigation
        request.setVisibleInDownloadsUi(true);

        //download path
        request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS.toString(), "/" + name);

        //file open when item on navigation is clicked
        request.allowScanningByMediaScanner();
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
       long downloadId = downloadManager.enqueue(request);

    }

输出

请参阅下图的输出

你可以在这里了解更多

于 2018-04-17T19:18:37.473 回答
0

您还可以在广播接收器下添加布尔或数字,条件以在完成每个下载任务后完成特定工作。

就像

private BroadcastReceiver onDownloadComplete = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        //Fetching the download id received with the broadcast
        long id = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1);
        //Checking if the received broadcast is for our enqueued download by matching download id
        if (downloadID == id) {
            //firstDownload is a boolean variable and assign each downloadManager as true or false

            if (firstDownload) {
                //First task downlaoded
            } else {
                //Second task downloaded


            }
        }


    };
于 2021-10-25T06:48:02.543 回答